[Qemu-devel] TCG: 64-bit temporaries on 32-bit target?

[Andreas Färber]

Hello,

On PowerPC there appear to be some "SPE" instructions that operate on  
64-bit registers while the rest of the target is 32-bit. In dyngen  
code, they can easily use T0_64 then.

In TCG however, cpu_T[0] is tl==i32 for ppc, only for ppc64 would  
cpu_T[0] work due to tl==i64. At the same time I was told I can't use  
tcg_gen_movi_i32 for tl cpu_T[n], so it seems we can't just  
unconditionally use i64 for cpu_T[0..2] either?

This issue prevents dyngen op_load_gpr_{T0,T1} from being removed  
because ppc64 gen_op_load_gpr64_{T0,T1} reuses them.

Any suggestions appreciated!

Andreas